This year's Serpentine Gallery Pavilion is not the visually bold statement of Jean Nouvel's bright red composition for 2010, or the playful engineering feat that was the Rem Koolhaas and Cecil Balmond version in 2006, featuring a moving helium balloon that reacted to the weather conditions. Yet, Peter Zumthor's proposal, Hortus Conclusus (meaning 'enclosed garden'), makes its mark within Serpentine Gallery Pavilion history for the simple reason that while all preceeding offerings have been a celebration of architecture, this one moves the focus to nature. Stemming from the Swiss architect's research into intimate spaces, as well as the architectural definition of a 'sanctuary', the Pavilion this year is a soulful space to relax and contemplate.

On entering the simple, black and low orthogonal volume, through slits cut into its otherwise blind facades, the visitor is led via a dark corridor through to a planted open courtyard. Long known for designs that sit in harmony within nature, like the Bruder Klaus Chapel in Mechernich, Germany or the Therme Vals in Switzerland, now Zumthor brings nature within his design, creating a calm, minimal structure that highlights the internal enclosed garden, lined by sheltered benches.

Located, as always outside the gallery, in the green plains of Hyde Park, the pavilion is essentially a garden within a garden. And while it does not have the visual thrill of its predecessors, it is an intriguing space, introducing a further level of seclusion and mystery into the serene park scenery.

The Pavilion's lavish centrepiece garden is the work of influential Dutch designer Piet Oudolf - who worked on the recently unveiled second section of New York's High Line park - while Arup has provided all the engineering support and specialist technical services in order to make the pavilion a reality.

The Serpentine's program famously presents work by architects who haven't yet built in the UK, which Peter Zumthor indeed hasn't - for now. The Secular Retreat house he is designing for holiday rental enterprise Living Architecture is well underway and planned to be available at the end of 2012. Till then, his Hortus Conclusus at the Serpentine is your best chance to sample Zumthor's unique architectural approach in Britain.